Description: An all-new 6-Series (E63) was introduced in 2003, filling the hole in the lineup left since the end of the 8-Series production. Based on the underpinnings of the E60, the new 6-Series was introduced with a 4.4 L 325 hp V8 engine for the 645Ci. In 2004, a more affordable inline six-cylinder engine was introduced in the 630i. This was soon followed by a convertible model (the E64), the first 6-Series with a removable top. Soon after its introduction, the 645Ci was replaced by the 650i, with a larger displacement (4.8 L) and 360 hp. The range-topping M6 arrived in late 2005, using the same V10 engine as the M5, with 507 PS (373 kW). In 2007 the 635d (Twin Turbo 3.0L Diesel) was introduced with 290 bhp and 430 lb ft which comprehensively outguns the 630i and can scare even the 650i on occasion with the added bonus of 41mpg.